I only tuned into what was happening midway through, so I missed the build up. From what I gathered, a customer ordered a mixed berry smoothie, but received a mixed berry oatmeal. I have no idea whether the customer ordered a smoothie or mistakenly ordered the oatmeal, but it shouldn't be a big deal. A little wasteful, maybe, but easily fixed.
From past experiences, K is very defensive when mistakes happen, but I've never seen her get this mouthy. K started speaking with a raised voice: "You ordered a smoothie - you're wrong. I always repeat back what you ordered. I said 'mixed oatmeal' and you did not correct me."
One of K's co-workers jumped in and said they'd have the smoothie up right away, and K commented, "The smoothie costs more, so she has to pay the difference." The customer seemed happy to do so (from her actions, at least; she wasn't arguing and was walking back to the register with her wallet out), but K's co-worker stepped in and said it was not necessary. K wasn't of the same mind: "No, she's pissing me off. She has to pay the difference."
The customer - who seemed really confused by what was going on and remained silent, except once or twice to politely state she had ordered a smoothie - got her smoothie. I had unfortunately chosen K's lineup and was next line, so I walked up to the register to order and was greeted with, "Can you believe some people? They can be so entitled."
I couldn't believe it. It's one thing to be annoyed with a customer, it's another thing to announce it to the entire building and try to get other customers in on your temper tantrum.
I wrote about the incident to corporate, but I'm pretty sure the store is a franchise and I don't think corporate will be able to do much. Everyone else who works there seems to be pretty blasé to K's attitude, so I don't know if calling the store will do anything.